Community vulnerability to hazards: introducing local expert knowledge into the equation

Assessments of social vulnerability have gained importance over the years, evolving from their initial emphasis on environmental factors surrounding natural disasters to a conceptual framework in which human agency plays a more decisive role. Up to know, most approaches to vulnerability were developed using an equally weighted approach in which each component contributes the same to vulnerability. To improve and enrich the information needed by authorities and stakeholders, we believe that a participatory approach would enhance our current understanding of vulnerability. Therefore, as an alternative to equally weighted approaches we propose and test the introduction of an expert panel to provide deeper insights into the relative contribution of vulnerability drivers. Our methodology has been applied to Aragn (Spain) at a municipality scale. The core of the analysis is a principal component analysis (PCA) applied to a set of socioeconomic and demographic variables. PCA allows extracting the main drivers of vulnerability in the region. Then, we introduce the role of a local expert panel by means of an analytical hierarchical process. Results are mapped and analyzed to (1) outline the spatial distribution of Community Vulnerability Index (CoVI), (2) determine the extent and location of vulnerable areas and (3) identify their main drivers. Overall, the introduction of the panel improves the ability of the method to differentiate strong (low CoVI) and weak (high CoVI) positions, compared to the original equally weighted approach.